The various embodiments described herein generally relate to electrical or electro-mechanical installations that are subject to service or repair during which components of such installations need to be bypassed or interrupted. More particularly, the various embodiments described herein relate to electronic wire bridges used to bypass or interrupt components in an electrical or electro-mechanical installation.
One example of an electrical or electro-mechanical installation is an elevator installation. Multi-story buildings are usually equipped with at least one elevator installation. In a generally known elevator installation, a suspension medium—such as a rope or flat belt-type rope—interconnects a counterweight and a cabin, and an electrical drive motor causes the suspension medium to move in order to thereby move the counterweight and the cabin up and down along a shaft or hoistway. An elevator controller of the elevator installation controls and monitors the operation of the elevator installation, e.g., by processing input signals received via communications network or signaling lines (e.g., from sensors, safety components (e.g., stop switches, door lock switches), etc.) and by generating control signals, which are fed to the communications network or the signaling lines.
An elevator installation in these multi-story buildings is subject to regular servicing or maintenance, testing or occasional repairs. During these procedures, it is common to use wire bridges or jumpers to bypass or interrupt certain components, e.g., a safety door switch to allow operation of the elevator installation with an open door, or a stop switch to allow a cabin to travel beyond a set stop. Once these procedures are finished, it is important that a technician removes all wire bridges, otherwise serious safety hazards exit. To minimize the risks caused by a jumper that has mistakenly been left in place, Wurtec, Inc., Ohio, USA, offers an electronic jumper that “times out” after a preprogrammed period of time.
Even though such an electronic jumper reduces the risk caused by a “forgotten” jumper, the time-out functionality of that jumper may not be sufficient to satisfy industry-standard safety requirements, especially when used for an extended period of time. There is, therefore, a need for an improved bridging or jumping technology that further reduces the potential risks associated with using jumpers in electrical or electro-mechanical installations, such as an elevator installation.